1. Field of the Invention
The invention relates to a locking device. More specifically, the invention relates to a locking device that is provided in one of two members to be engaged with each other, and is adapted to receive a striker provided on the other member so as to lock the striker in place.
2. Description of the Related Art
For example, a technology as disclosed in Japanese Patent Application Publication No. 4-76173 (JP-A-4-76173) is known as being applicable to this type of locking device. The locking device as disclosed in this publication includes a base plate having a recessed portion that can receive a striker, and a hook and a pole supported by respective support shafts so as to be rotatable relative to the base plate. The hook and the pole are normally biased under bias force of respective springs in opposite rotational directions. The hook is held in a rotational position at which a part of the hook extends over the recessed portion of the base plate.
When the striker is pushed into the recessed portion of the base plate relative to the base plate, the hook is pushed and rotated according to the movement of the striker. As a result, a part of the hook is turned and located behind the striker so that the recessed portion is closed. In this closed position, the pole is engaged with the hook under bias force, so that the hook is held in a condition in which rotation of the hook is inhibited by the pole.
However, according to the related art as disclosed in the above-indicated publication, the hook is normally held in a condition in which the hook is engaged with the pole under bias force of the spring, such that the hook is pressed against a protrusion formed on the pole. In this condition, the hook is inhibited from rotating since the pole is pressed against an outer circumferential portion of the hook. Therefore, when the hook is pushed in and rotated by the striker, large frictional resistance is generated between the hook and the pole during sliding movements thereof, and the hook may not be smoothly rotated when the striker moves into the recessed portion of the hook.